1. Technical Field
This present invention is directed to a pointer for an instrument panel which is actively lighted and, more specifically, an actively lighted pointer including a flex circuit.
2. Discussion
Vehicle manufactures continually strive to differentiate vehicles in the marketplace by providing unique styling and aesthetic features. As part of this differentiation many manufactures attempt to provide a unique cockpit look and feel for the operator of the vehicle. As part of this unique look and feel, each vehicle manufacturer attempts to have a different appearance to their instrument panels and gauges, however, manufacturers have been limited in differentiating instruments panels and gauges by the types, sizes and requirements of available pointers, particularly for pointers that are lighted. The amount of required space for each pointer sweeping about its rotational axis, and in particular for speedometer pointers, also limited the available design options.
Traditionally, instrument panels and gauges were back lighted, which limited the number of design options for instrument panels. The pointers are generally substantially located above the surface plate of the instrument panel and lighted pointers received light from under the surface of the instrument panel, generally through a light pipe extending cylindrically upward about the rotational axis. The design requirements for lighted pointers significantly limited the style of gauges and pointers that could be used. In particular for longer lighted pointers, such as most speedometer pointers, larger light pipes were required and the pointers were difficult to uniformly and brightly light along their length. Furthermore, due to the length of some pointers, and in particular speedometer pointers, any bends, such as bends required if a portion of the pointer was located under the surface plate of the instrument panel, decreased the available light along the length of the pointer and made the pointer difficult to light. Therefore, especially for speedometer pointers, most speedometer gauges were significantly constrained in style and function and they also occupied a large space on the instrument panel.
To differentiate instrument panels and gauges, some manufacturers have attempted to actively light pointers, in particular longer pointers. Actively lighted pointers generally include an LED within the pointer, typically on the moveable portion of the pointer some distance from the rotational axis of the pointer. An actively lighted pointer is desirable because it allows unique pointers to be developed, thereby providing differentiation of gauges and instrument panels between manufacturers. Actively lighted pointers also can provide greater contrast and a brighter pointer for the user.
To light the pointer, the LED must receive power, yet be powered in such a way that the pointer is free to operationally rotate as needed over a significant number of cycles. The power supply to the LED in the pointer must also be sufficiently small, minimizing the amount of space required within the instrument panel. One problem with using actively lighted pointers is providing a durable power supply between the LED and a control circuit that requires minimal space. As illustrated in FIG. 1, labeled as Prior Art, to power LEDs in actively lighted pointers, typically a flex circuit is wound loosely around the rotational axis like a clock spring. This clock spring approach provides the necessary slack in the power supply to allow the pointer to sweep back and forth freely. One problem with the clock spring technique is that it requires a large open space along the pointer drive motor shaft underneath the pointer to allow for wrapping of the flex and any winding control features to maintain an orderly flex circuit winding action. As vehicle instrument panels include more functions and also have become thinner, there is a need for a flex circuit power supply that minimizes the amount of the space and in particular minimizes the amount of space required around the drive shaft or axis of rotation of the pointer.